Extraction and in Vitro Adsorption Properties of Dietary Fiber from Phyllanthus emblica Linn. Pomace

An investigation was carried out to optimize the extraction process of dietary fiber from Phyllanthus emblica Linn. pomace, and the physicochemical properties and in vitro adsorption capacity of Phyllanthus emblica Linn. pomace, total dietary fiber (TDF), insoluble dietary fiber (IDF), and soluble dietary fiber (SDF) were investigated. The results showed that the optimal extraction process using alkali method was: Concentration of NaOH 8 g/L, material-to-liquid ratio of 1:35 (g:mL), treatment at 70 °C for 40 min, and the yield of IDF and SDF were 61.72%±0.04% and 17.57%±0.03%, respectively. Phyllanthus emblica Linn. pomace and its dietary fiber both had good hydration properties and oil-holding capacity. TDF had the lowest water holding and the highest swelling capacity significantly different from Phyllanthus emblica Linn. pomace, SDF and IDF (P<0.05). SDF had lowly capacity to oil-holding, swelling and fat, however under simulated stomach (pH2) which had the higher adsorption capacity for cholesterol and NO₂^- than Phyllanthus emblica Linn. pomace, TDF and IDF (P<0.05). The adsorption capacity of Phyllanthus emblica Linn. pomace and its dietary fiber on cholesterol and NO₂⁻ was related with pH in vitro. The cholesterol adsorption capacity of TDF and SDF were higher under simulating stomach pH, while the adsorption capacity of Phyllanthus emblica Linn. pomace and IDF on cholesterol were higher under simulating small intestine. The Phyllanthus emblica Linn. pomace and its dietary fiber had higher adsorption capacity on NO₂⁻ under stomach pH than simulated small intestinal pH. This paper studied the extraction and properties of dietary fiber from Phyllanthus emblica Linn. pomace, which could provide some theoretical reference for its application in health food.